agura commented on a change in pull request #203: URL: https://github.com/apache/ignite-3/pull/203#discussion_r673264578
########## File path: modules/metastorage-server/src/main/java/org/apache/ignite/internal/metastorage/server/persistence/RocksDBKeyValueStorage.java ########## @@ -0,0 +1,1090 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You under the Apache License, Version 2.0 + * (the "License"); you may not use this file except in compliance with + * the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.ignite.internal.metastorage.server.persistence; + +import java.io.IOException; +import java.nio.charset.StandardCharsets; +import java.nio.file.Files; +import java.nio.file.Path; +import java.nio.file.Paths; +import java.util.ArrayList; +import java.util.Arrays; +import java.util.Collection; +import java.util.Collections; +import java.util.Comparator; +import java.util.List; +import java.util.Map; +import java.util.TreeSet; +import java.util.concurrent.CompletableFuture; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.locks.ReadWriteLock; +import java.util.concurrent.locks.ReentrantReadWriteLock; +import org.apache.ignite.internal.metastorage.server.Condition; +import org.apache.ignite.internal.metastorage.server.Entry; +import org.apache.ignite.internal.metastorage.server.KeyValueStorage; +import org.apache.ignite.internal.metastorage.server.Operation; +import org.apache.ignite.internal.metastorage.server.Value; +import org.apache.ignite.internal.metastorage.server.WatchEvent; +import org.apache.ignite.internal.util.Cursor; +import org.apache.ignite.internal.util.IgniteUtils; +import org.apache.ignite.lang.IgniteBiTuple; +import org.apache.ignite.lang.IgniteInternalException; +import org.jetbrains.annotations.NotNull; +import org.jetbrains.annotations.Nullable; +import org.jetbrains.annotations.TestOnly; +import org.rocksdb.ColumnFamilyDescriptor; +import org.rocksdb.ColumnFamilyHandle; +import org.rocksdb.ColumnFamilyOptions; +import org.rocksdb.DBOptions; +import org.rocksdb.EnvOptions; +import org.rocksdb.IngestExternalFileOptions; +import org.rocksdb.Options; +import org.rocksdb.ReadOptions; +import org.rocksdb.RocksDB; +import org.rocksdb.RocksDBException; +import org.rocksdb.RocksIterator; +import org.rocksdb.Snapshot; +import org.rocksdb.SstFileWriter; +import org.rocksdb.WriteBatch; +import org.rocksdb.WriteOptions; + +import static org.apache.ignite.internal.metastorage.server.Value.TOMBSTONE; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.appendLong; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.bytesToLong; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.bytesToValue; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.find; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.forEach; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.getAsLongs; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.keyToRocksKey; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.longToBytes; +import static org.apache.ignite.internal.metastorage.server.persistence.RocksStorageUtils.valueToBytes; +import static org.apache.ignite.internal.metastorage.server.persistence.StorageColumnFamilyType.DATA; +import static org.apache.ignite.internal.metastorage.server.persistence.StorageColumnFamilyType.INDEX; +import static org.apache.ignite.internal.util.ArrayUtils.LONG_EMPTY_ARRAY; + +/** + * Key-value storage based on RocksDB. + * Keys are stored with revision. + * Values are stored in the default column family with an update counter and a boolean flag which represents + * whether this record is a tombstone. + * <br> + * Key: [8 bytes revision, N bytes key itself]. + * <br> + * Value: [8 bytes update counter, 1 byte tombstone flag, N bytes value]. + * <br> + * The mapping from the key to the set of the storage's revisions is stored in the "index" column family. + * A key represents the key of an entry and the value is a {@code byte[]} that represents a {@code long[]} where every + * item is a revision of the storage. + */ +public class RocksDBKeyValueStorage implements KeyValueStorage { + /** Suffix for the temporary snapshot folder */ + private static final String TMP_SUFFIX = ".tmp"; + + /** A revision to store with system entries. */ + private static final long SYSTEM_REVISION_MARKER_VALUE = -1; + + /** Revision key. */ + private static final byte[] REVISION_KEY = keyToRocksKey( + SYSTEM_REVISION_MARKER_VALUE, + "SYSTEM_REVISION_KEY".getBytes(StandardCharsets.UTF_8) + ); + + /** Update counter key. */ + private static final byte[] UPDATE_COUNTER_KEY = keyToRocksKey( + SYSTEM_REVISION_MARKER_VALUE, + "SYSTEM_UPDATE_COUNTER_KEY".getBytes(StandardCharsets.UTF_8) + ); + + static { + RocksDB.loadLibrary(); + } + + /** RockDB options. */ + private final DBOptions options; + + /** RocksDb instance. */ + private final RocksDB db; + + /** Data column family. */ + private final ColumnFamily data; + + /** Index column family. */ + private final ColumnFamily index; + + /** RW lock. */ + private final ReadWriteLock rwLock = new ReentrantReadWriteLock(); + + /** Thread-pool for snapshot operations execution. */ + private final ExecutorService snapshotExecutor = Executors.newFixedThreadPool(2); + + /** + * Special value for the revision number which means that operation should be applied + * to the latest revision of an entry. + */ + private static final long LATEST_REV = -1; + + /** Lexicographic order comparator. */ + static final Comparator<byte[]> CMP = Arrays::compare; + + /** Path to the rocksdb database. */ + private final Path dbPath; + + /** Revision. Will be incremented for each single-entry or multi-entry update operation. */ + private long rev; + + /** Update counter. Will be incremented for each update of any particular entry. */ + private long updCntr; + + /** + * Constructor. + * + * @param dbPath RocksDB path. + */ + public RocksDBKeyValueStorage(Path dbPath) { + try { + options = new DBOptions() + .setCreateMissingColumnFamilies(true) + .setCreateIfMissing(true); + + this.dbPath = dbPath; + + Options dataOptions = new Options().setCreateIfMissing(true) + // The prefix is the revision of an entry, so prefix length is the size of a long + .useFixedLengthPrefixExtractor(Long.BYTES); + + ColumnFamilyOptions dataFamilyOptions = new ColumnFamilyOptions(dataOptions); + + Options indexOptions = new Options().setCreateIfMissing(true); + + ColumnFamilyOptions indexFamilyOptions = new ColumnFamilyOptions(indexOptions); + + List<ColumnFamilyDescriptor> descriptors = Arrays.asList( + new ColumnFamilyDescriptor(DATA.nameAsBytes(), dataFamilyOptions), + new ColumnFamilyDescriptor(INDEX.nameAsBytes(), indexFamilyOptions) + ); + + var handles = new ArrayList<ColumnFamilyHandle>(); + + // Delete existing data, relying on the raft's snapshot and log playback + destroyRocksDB(); + + this.db = RocksDB.open(options, dbPath.toAbsolutePath().toString(), descriptors, handles); + + data = new ColumnFamily(db, handles.get(0), DATA, dataFamilyOptions, dataOptions); + + index = new ColumnFamily(db, handles.get(1), INDEX, indexFamilyOptions, indexOptions); + } + catch (Exception e) { + try { + close(); + } + catch (Exception exception) { + e.addSuppressed(exception); + } + + throw new IgniteInternalException("Failed to start the storage", e); + } + } + + /** + * Clear the RocksDB instance. + * The major difference with directly deleting the DB directory manually is that + * destroyDB() will take care of the case where the RocksDB database is stored + * in multiple directories. For instance, a single DB can be configured to store + * its data in multiple directories by specifying different paths to + * DBOptions::db_paths, DBOptions::db_log_dir, and DBOptions::wal_dir. + * + * @throws RocksDBException If failed. + */ + private void destroyRocksDB() throws RocksDBException { + try (Options opt = new Options()) { + RocksDB.destroyDB(dbPath.toString(), opt); + } + } + + /** {@inheritDoc} */ + @Override public void close() throws Exception { + IgniteUtils.shutdownAndAwaitTermination(snapshotExecutor, 10, TimeUnit.SECONDS); + + IgniteUtils.closeAll(data, index, db, options); + } + + /** {@inheritDoc} */ + @NotNull + @Override public CompletableFuture<Void> snapshot(Path snapshotPath) { + Path tempPath = Paths.get(snapshotPath.toString() + TMP_SUFFIX); + + // Create a RocksDB point-in-time snapshot + Snapshot snapshot = db.getSnapshot(); + + return CompletableFuture.runAsync(() -> { + // (Re)create the temporary directory + IgniteUtils.deleteIfExists(tempPath); + + try { + Files.createDirectories(tempPath); + } + catch (IOException e) { + throw new IgniteInternalException("Failed to create directory: " + tempPath, e); + } + }, snapshotExecutor).thenCompose(aVoid -> + // Create futures for capturing SST snapshots of the column families + CompletableFuture.allOf(createSstFile(data, snapshot, tempPath), createSstFile(index, snapshot, tempPath))) + .whenComplete((aVoid, throwable) -> { + // Release a snapshot + db.releaseSnapshot(snapshot); + + // Snapshot is not actually closed here, because a Snapshot instance doesn't own a pointer, the + // database does. Calling close to maintain the AutoCloseable semantics + snapshot.close(); + + if (throwable != null) + return; + + // Delete snapshot directory if it already exists + IgniteUtils.deleteIfExists(snapshotPath); + + try { + // Rename the temporary directory + Files.move(tempPath, snapshotPath); + } + catch (IOException e) { + throw new IgniteInternalException("Failed to rename: " + tempPath + " to " + snapshotPath, e); + } + }); + } + + /** + * Create an SST file for the column family. + * + * @param columnFamily Column family. + * @param snapshot Point-in-time snapshot. + * @param path Directory to put the SST file in. + * @return Future representing pending completion of the operation. + */ + private CompletableFuture<Void> createSstFile(ColumnFamily columnFamily, Snapshot snapshot, Path path) { + return CompletableFuture.runAsync(() -> { + try ( + EnvOptions envOptions = new EnvOptions(); + Options options = new Options(); + ReadOptions readOptions = new ReadOptions().setSnapshot(snapshot); + RocksIterator it = columnFamily.newIterator(readOptions); + SstFileWriter sstFileWriter = new SstFileWriter(envOptions, options) + ) { + Path sstFile = path.resolve(columnFamily.name()); + + sstFileWriter.open(sstFile.toString()); + + it.seekToFirst(); + + forEach(it, sstFileWriter::put); + + sstFileWriter.finish(); + } + catch (Throwable t) { + throw new IgniteInternalException("Failed to write snapshot: " + t.getMessage(), t); + } + }, snapshotExecutor); + } + + /** {@inheritDoc} */ + @Override public void restoreSnapshot(Path path) { + rwLock.writeLock().lock(); + + try (IngestExternalFileOptions ingestOptions = new IngestExternalFileOptions()) { + for (ColumnFamily family : Arrays.asList(data, index)) { + Path snapshotPath = path.resolve(family.name()); + + if (!Files.exists(snapshotPath)) + throw new IgniteInternalException("Snapshot not found: " + snapshotPath); + + family.ingestExternalFile(Collections.singletonList(snapshotPath.toString()), ingestOptions); + } + + rev = bytesToLong(data.get(REVISION_KEY)); + + updCntr = bytesToLong(data.get(UPDATE_COUNTER_KEY)); + } + catch (RocksDBException e) { + throw new IgniteInternalException("Fail to ingest sst file at path: " + path, e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @Override public long revision() { + return rev; + } + + /** {@inheritDoc} */ + @Override public long updateCounter() { + return updCntr; + } + + /** {@inheritDoc} */ + @Override public void put(byte[] key, byte[] value) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + + long cntr = updCntr + 1; + + addDataToBatch(batch, key, value, curRev, cntr); + + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, cntr); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** + * Adds a revision to the keys index. + * + * @param batch Write batch. + * @param key Key. + * @param curRev New revision for key. + */ + private void updateKeysIndex(WriteBatch batch, byte[] key, long curRev) { + try { + // Get the revisions current value + byte @Nullable [] array = index.get(key); + + // Store the new value + index.put(batch, key, appendLong(array, curRev)); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + } + + /** + * Fills the batch with system values (the update counter and the revision) and writes it to the db. + * + * @param batch Write batch. + * @param newRev New revision. + * @param newCntr New update counter. + * @throws RocksDBException If failed. + */ + private void fillAndWriteBatch(WriteBatch batch, long newRev, long newCntr) throws RocksDBException { + try (WriteOptions opts = new WriteOptions()) { + data.put(batch, UPDATE_COUNTER_KEY, longToBytes(newCntr)); + data.put(batch, REVISION_KEY, longToBytes(newRev)); + + db.write(opts, batch); + + rev = newRev; + updCntr = newCntr; + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Entry getAndPut(byte[] key, byte[] value) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + long cntr = updCntr + 1; + + long[] revs = getRevisions(key); + + long lastRev = revs.length == 0 ? 0 : lastRevision(revs); + + addDataToBatch(batch, key, value, curRev, cntr); + + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, cntr); + + // Return previous value. + return doGetValue(key, lastRev); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @Override public void putAll(List<byte[]> keys, List<byte[]> values) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + + long counter = addAllToBatch(batch, keys, values, curRev); + + for (byte[] key : keys) + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Collection<Entry> getAndPutAll(List<byte[]> keys, List<byte[]> values) { + Collection<Entry> res; + + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + + res = doGetAll(keys, curRev); + + long counter = addAllToBatch(batch, keys, values, curRev); + + for (byte[] key : keys) + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + + return res; + } + + /** {@inheritDoc} */ + @NotNull + @Override public Entry get(byte[] key) { + rwLock.readLock().lock(); + + try { + return doGet(key, LATEST_REV, false); + } + finally { + rwLock.readLock().unlock(); + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Entry get(byte[] key, long rev) { + rwLock.readLock().lock(); + + try { + return doGet(key, rev, true); + } + finally { + rwLock.readLock().unlock(); + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Collection<Entry> getAll(List<byte[]> keys) { + return doGetAll(keys, LATEST_REV); + } + + /** {@inheritDoc} */ + @NotNull + @Override public Collection<Entry> getAll(List<byte[]> keys, long revUpperBound) { + return doGetAll(keys, revUpperBound); + } + + /** {@inheritDoc} */ + @Override public void remove(byte[] key) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + long counter = updCntr + 1; + + if (addToBatchForRemoval(batch, key, curRev, counter)) { + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Entry getAndRemove(byte[] key) { + rwLock.writeLock().lock(); + + try { + Entry e = doGet(key, LATEST_REV, false); + + if (e.empty() || e.tombstone()) + return e; + + return getAndPut(key, TOMBSTONE); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @Override public void removeAll(List<byte[]> keys) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + + List<byte[]> existingKeys = new ArrayList<>(keys.size()); + + long counter = updCntr; + + for (byte[] key : keys) { + if (addToBatchForRemoval(batch, key, curRev, counter + 1)) { + existingKeys.add(key); + + counter++; + } + } + + for (byte[] key : existingKeys) + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @NotNull + @Override public Collection<Entry> getAndRemoveAll(List<byte[]> keys) { + Collection<Entry> res = new ArrayList<>(keys.size()); + + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + long curRev = rev + 1; + + List<byte[]> existingKeys = new ArrayList<>(keys.size()); + + List<byte[]> vals = new ArrayList<>(keys.size()); + + for (byte[] key : keys) { + Entry e = doGet(key, LATEST_REV, false); + + res.add(e); + + if (e.empty() || e.tombstone()) + continue; + + existingKeys.add(key); + + vals.add(TOMBSTONE); + } + + long counter = addAllToBatch(batch, existingKeys, vals, curRev); + + for (byte[] key : existingKeys) + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + + return res; + } + + /** {@inheritDoc} */ + @Override public boolean invoke(Condition condition, Collection<Operation> success, Collection<Operation> failure) { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + Entry e = get(condition.key()); + + boolean branch = condition.test(e); + + Collection<Operation> ops = branch ? success : failure; + + long curRev = rev + 1; + + boolean modified = false; + + long counter = updCntr; + + List<byte[]> updatedKeys = new ArrayList<>(); + + for (Operation op : ops) { + byte[] key = op.key(); + + switch (op.type()) { + case PUT: + counter++; + + addDataToBatch(batch, key, op.value(), curRev, counter); + + updatedKeys.add(key); + + modified = true; + + break; + + case REMOVE: + counter++; + + boolean removed = addToBatchForRemoval(batch, key, curRev, counter); + + if (!removed) + counter--; + else + updatedKeys.add(key); + + modified |= removed; + + break; + + case NO_OP: + break; + + default: + throw new IllegalArgumentException("Unknown operation type: " + op.type()); + } + } + + if (modified) { + for (byte[] key : updatedKeys) + updateKeysIndex(batch, key, curRev); + + fillAndWriteBatch(batch, curRev, counter); + } + + return branch; + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** {@inheritDoc} */ + @Override public Cursor<Entry> range(byte[] keyFrom, byte[] keyTo) { + return new RangeCursor(this, keyFrom, keyTo, rev); + } + + /** {@inheritDoc} */ + @Override public Cursor<Entry> range(byte[] keyFrom, byte[] keyTo, long revUpperBound) { + return new RangeCursor(this, keyFrom, keyTo, revUpperBound); + } + + /** {@inheritDoc} */ + @Override public Cursor<WatchEvent> watch(byte[] keyFrom, byte @Nullable [] keyTo, long rev) { + assert keyFrom != null : "keyFrom couldn't be null."; + assert rev > 0 : "rev must be positive."; + + return new WatchCursor(this, rev, k -> + CMP.compare(keyFrom, k) <= 0 && (keyTo == null || CMP.compare(k, keyTo) < 0) + ); + } + + /** {@inheritDoc} */ + @Override public Cursor<WatchEvent> watch(byte[] key, long rev) { + assert key != null : "key couldn't be null."; + assert rev > 0 : "rev must be positive."; + + return new WatchCursor(this, rev, k -> CMP.compare(k, key) == 0); + } + + /** {@inheritDoc} */ + @Override public Cursor<WatchEvent> watch(Collection<byte[]> keys, long rev) { + assert keys != null && !keys.isEmpty() : "keys couldn't be null or empty: " + keys; + assert rev > 0 : "rev must be positive."; + + TreeSet<byte[]> keySet = new TreeSet<>(CMP); + + keySet.addAll(keys); + + return new WatchCursor(this, rev, keySet::contains); + } + + /** {@inheritDoc} */ + @Override public void compact() { + rwLock.writeLock().lock(); + + try (WriteBatch batch = new WriteBatch()) { + try (RocksIterator iterator = index.newIterator()) { + iterator.seekToFirst(); + + forEach(iterator, (key, value) -> compactForKey(batch, key, getAsLongs(value))); + } + + fillAndWriteBatch(batch, rev, updCntr); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + finally { + rwLock.writeLock().unlock(); + } + } + + /** + * Adds a key to a batch marking the value as a tombstone. + * + * @param batch Write batch. + * @param key Target key. + * @param curRev Revision. + * @param counter Update counter. + * @return {@code true} if an entry can be deleted. + * @throws RocksDBException If failed. + */ + private boolean addToBatchForRemoval(WriteBatch batch, byte[] key, long curRev, long counter) throws RocksDBException { + Entry e = doGet(key, LATEST_REV, false); + + if (e.empty() || e.tombstone()) + return false; + + addDataToBatch(batch, key, TOMBSTONE, curRev, counter); + + return true; + } + + /** + * Compacts all entries by the given key, removing all previous revisions and deleting the last entry if it is + * a tombstone. + * + * @param batch Write batch. + * @param key Target key. + * @param revs Revisions. + * @throws RocksDBException If failed. + */ + private void compactForKey(WriteBatch batch, byte[] key, long[] revs) throws RocksDBException { + long lastRev = lastRevision(revs); + + for (int i = 0; i < revs.length - 1; i++) + data.delete(batch, keyToRocksKey(revs[i], key)); + + byte[] rocksKey = keyToRocksKey(lastRev, key); + + Value value = bytesToValue(data.get(rocksKey)); + + if (value.tombstone()) { + index.delete(batch, rocksKey); + + index.delete(batch, key); + } + else + index.put(batch, key, longToBytes(lastRev)); + } + + /** + * Gets all entries with given keys and a revision. + * + * @param keys Target keys. + * @param rev Target revision. + * @return Collection of entries. + */ + @NotNull + private Collection<Entry> doGetAll(Collection<byte[]> keys, long rev) { + assert keys != null : "keys list can't be null."; + assert !keys.isEmpty() : "keys list can't be empty."; + assert rev > 0 || rev == LATEST_REV : "Revision must be positive or " + LATEST_REV + '.'; + + Collection<Entry> res = new ArrayList<>(keys.size()); + + rwLock.readLock().lock(); + + try { + for (byte[] key : keys) + res.add(doGet(key, rev, false)); + } + finally { + rwLock.readLock().unlock(); + } + + return res; + } + + /** + * Gets the value by key and revision. + * + * @param key Target key. + * @param rev Target revision. + * @param exactRev {@code true} if searching for exact revision, {@code false} if rev is an upper bound (inclusive). + * @return Value. + */ + @NotNull + Entry doGet(byte[] key, long rev, boolean exactRev) { + assert rev == LATEST_REV && !exactRev || rev > LATEST_REV : + "Invalid arguments: [rev=" + rev + ", exactRev=" + exactRev + ']'; + + long[] revs; + try { + revs = getRevisions(key); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + + if (revs == null || revs.length == 0) + return Entry.empty(key); + + long lastRev; + + if (rev == LATEST_REV) + lastRev = lastRevision(revs); + else + lastRev = exactRev ? rev : maxRevision(revs, rev); + + // lastRev can be -1 if maxRevision return -1. + if (lastRev == -1) + return Entry.empty(key); + + return doGetValue(key, lastRev); + } + + /** + * Get a list of the revisions of the entry corresponding to the key. + * + * @param key Key. + * @return List of the revisions. + * @throws RocksDBException If failed to perform {@link RocksDB#get(ColumnFamilyHandle, byte[])}. + */ + private long[] getRevisions(byte[] key) throws RocksDBException { + byte[] revisions = index.get(key); + + if (revisions == null) + return LONG_EMPTY_ARRAY; + + return getAsLongs(revisions); + } + + /** + * Returns maximum revision which must be less or equal to {@code upperBoundRev}. If there is no such revision then + * {@code -1} will be returned. + * + * @param revs Revisions list. + * @param upperBoundRev Revision upper bound. + * @return Maximum revision or {@code -1} if there is no such revision. + */ + static long maxRevision(long[] revs, long upperBoundRev) { + for (int i = revs.length - 1; i >= 0; i--) { + long rev = revs[i]; + + if (rev <= upperBoundRev) + return rev; + } + + return -1; + } + + /** + * Gets the value by a key and a revision. + * + * @param key Target key. + * @param revision Target revision. + * @return Entry. + */ + @NotNull + Entry doGetValue(byte[] key, long revision) { + if (revision == 0) + return Entry.empty(key); + + byte[] valueBytes; + + try { + valueBytes = data.get(keyToRocksKey(revision, key)); + } + catch (RocksDBException e) { + throw new IgniteInternalException(e); + } + + if (valueBytes == null || valueBytes.length == 0) + return Entry.empty(key); + + Value lastVal = bytesToValue(valueBytes); + + if (lastVal.tombstone()) + return Entry.tombstone(key, revision, lastVal.updateCounter()); + + return new Entry(key, lastVal.bytes(), revision, lastVal.updateCounter()); + } + + /** + * Adds an entry to the batch. + * + * @param batch Write batch. + * @param key Key. + * @param value Value. + * @param curRev Revision. + * @param cntr Update counter. + * @throws RocksDBException If failed. + */ + private void addDataToBatch(WriteBatch batch, byte[] key, byte[] value, long curRev, long cntr) throws RocksDBException { + byte[] rocksKey = keyToRocksKey(curRev, key); + + byte[] rocksValue = valueToBytes(value, cntr); + + data.put(batch, rocksKey, rocksValue); + } + + /** + * Adds all entries to the batch. + * + * @param batch Write batch. + * @param keys Keys. + * @param values Values. + * @param curRev Revision. + * @return New update counter value. + * @throws RocksDBException If failed. + */ + private long addAllToBatch(WriteBatch batch, List<byte[]> keys, List<byte[]> values, long curRev) throws RocksDBException { + long counter = this.updCntr; + + for (int i = 0; i < keys.size(); i++) { + counter++; + + byte[] key = keys.get(i); + + byte[] bytes = values.get(i); + + addDataToBatch(batch, key, bytes, curRev, counter); + } + + return counter; + } + + /** + * Gets a ceiling (higher or equal) entry for a key in the keys index. + * + * @param keyFrom Key. + * @return Higher or equal entry. + */ + @Nullable + Map.Entry<byte[], long[]> revisionCeilingEntry(byte[] keyFrom) { + return higherOrCeiling(keyFrom, false); + } + + /** + * Gets a higher entry for a key in the keys index. + * + * @param key Key. + * @return Higher entry. + */ + @Nullable + Map.Entry<byte[], long[]> revisionHigherEntry(byte[] key) { + return higherOrCeiling(key, true); + } + + /** + * Gets a higher or ceiling entry for a key in the keys index, depending on the strictlyHigher parameter. + * + * @param key + * @param strictlyHigher {@code true} for a strictly higher entry, {@code false} for a ceiling one. + * @return Entry. Review comment: Please fix javadoc and describe return value correctly -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
